The present invention concerns a method for measuring pressure using a capacitive pressure transducer and a pressure measuring device comprising a capacitive pressure transducer according to the preamble of claim 10.
For considerable time it has been known in the art to measure the pressure of a fluid by monitoring the capacity of a capacitive pressure transducer comprising a membrane whose deformation depends on the pressure where the monitoring of the capacity involves applying an AC voltage to the capacitive pressure transducer. A description of the generic method and device can be found in: Hans-Werner Drawin: `Kondensator-Membran-Manometer fur Druckmessungen im Hoch- und Feinvakuumgebiet, unabhangig von der Gasart`, Vakuum-Technik 7/8 (1958).
However, the result of such measurement can be affected by resonance of the capacitive pressure transducer, in particular when very small pressures are being measured using very thin membranes. It has been found that a 1 torr transducer of the generic type is very sensitive to resonance. Neither a method nor a device have been known so far where erroneous readings caused by resonance were compensated for.